How to Choose Between RTK and GPS: 8 Points to Avoid Failure

Table of Contents

• First, outline the differences between RTK and GPS.

• Why failures occur when deciding how to use something

• Point 1: Select based on accuracy requirements

• Point 2: Choose based on the type of work

• Point 3 Choose based on the on-site environment

• Point 4: Choose based on immediacy

• Point 5: Choose based on the operational structure

• Point 6: Choose based on communication conditions

• Point 7: Choose according to the intended use of the deliverable

• Point 8: Choose based on future expandability

• Decision flow for choosing between RTK and GPS

• Summary

First, clarify the differences between RTK and GPS

RTK and GPS are often discussed as technologies for determining position, but in practical terms they do not mean the same thing. Because the two are frequently compared side-by-side in searches, they tend to be understood as similar, but on the ground the required accuracy, workflow, necessary preparations, and suitable applications differ significantly. As a result, choosing the wrong one can mean that data you think you've measured becomes unusable, or you end up adopting an unnecessarily labor-intensive operation.

First, what I want to clarify is that the term GPS is used broadly in the field. In general, satellite-based positioning as a whole is sometimes called GPS, but in practice, when GPS is compared it often refers to the basic satellite positioning that determines a position standalone without using correction information. RTK, on the other hand, is a method that obtains coordinates with higher accuracy by utilizing not only signals from satellites but also reference stations and correction information.

This difference is not merely a matter of terminology. Whether what’s needed on site is rough position awareness or centimeter-level position control completely changes the appropriate choice. For example, if you only want to record your position while walking over a wide area, a standard GPS may be sufficient. However, for tasks such as setting out structures, construction management, as-built verification, or checking positions close to boundaries—situations where positional deviations can lead to practical problems—RTK is often required.

In short, choosing between RTK and GPS is not about comparing which performs better, but about selecting the means that are necessary and sufficient for the purpose. Higher accuracy is not always better, and convenience is not always the right choice. Only by judging based on site conditions, the nature of the work, and the intended use of the deliverables can you achieve a realistic implementation and stable operation.

Why Failures Occur When Choosing Which One to Use

The reason decisions between RTK and GPS fail is that they are based solely on accuracy. Many field practitioners understand that RTK is high‑precision and GPS is simpler, but choosing only on that basis leads to unexpected problems on site. This is because in practice many factors besides accuracy interact: securing communications, sky visibility, stability of observations, crew size, processing workflow, and the required level of the final deliverables.

One common mistake is introducing an overly high-precision system for a task that really only requires a rough position check. In that case, only the burden of preparation and operation increases, and the speed of the work can decrease. Conversely, if you prioritize simplicity and rely on a general GPS, you may find later that positional accuracy is insufficient and need to perform re-measurement or supplementary measurements. What seems convenient at first can, when rework occurs, ultimately increase both the man-hours required and the overall burden.

Another mistake is using observation data without correctly understanding what the observations mean. When a position is shown on the screen, it’s easy to assume that you have obtained the correct coordinates, but in fact the quality can vary greatly depending on the positioning status and the surrounding environment. In particular, near buildings, under trees, beside slopes, in valleys, or in areas where equipment is densely clustered, satellite reception conditions tend to deteriorate, and even if the device appears to be functioning normally, you may not get stable values.

Furthermore, it is problematic that the on-site decision criteria remain ambiguous in practice. If there is no common understanding among personnel about which tasks should use RTK and which can be adequately handled with GPS, judgments will vary even within the same company. As a result, the quality of deliverables may be inconsistent, making it difficult to reconcile them in subsequent processes.

What's important, therefore, is to think of RTK and GPS not as different pieces of equipment but in terms of how to use them differently within your workflow. By following the eight points explained below, you can more easily avoid choices that don't suit the site and greatly reduce the risk of unnecessary rework or insufficient accuracy.

Point 1: Choose based on accuracy requirements

When deciding whether to use RTK or GPS, the first thing to consider is the required level of accuracy. However, the important point here is not to choose the most accurate method possible, but to specify in concrete terms the accuracy needed for the task. In practice, high accuracy is not an end in itself. What matters is whether the accuracy reaches a level that allows necessary decisions, recording, management, and inspections to be carried out without problems.

For example, in tasks where you patrol the site and record the approximate locations of equipment and anomalies, deviations of several meters (several ft) may not be a major issue. In such cases, the simplicity of GPS is a major advantage. It requires little preparation, can be used immediately, and allows efficient coverage of a wide area. On the other hand, for verifying construction positions, work based on control points, records that need to be consistent with drawings or coordinate systems, and acquisition of position information related to as-built measurements, deviations of several meters (several ft) are not acceptable. In these situations, RTK tends to be the default.

In practical decision-making, you first need to consider what the data will be used for. The required accuracy varies depending on whether you only want to retain positions as internal reference material, use them overlaid with other survey results or design data, or use them for inspection or explanatory materials. If the position information acquired on site will be treated as the basis for coordinates in later processes, it is safer to choose RTK from the outset.

Accuracy requirements need to be considered not only in the horizontal direction but also in the vertical direction. Some tasks only require knowing the planar position, while others make elevation differences and height management important. In situations where height matters, simply being able to obtain a position is insufficient, and more stable, high-precision operation is required.

In other words, the first step in distinguishing which to use is to translate the task’s objective into terms of positional accuracy. Simply clarifying whether an approximate position is sufficient, whether you need a level that can be overlaid on drawings, or whether you need a level usable for construction management will make it easier to see whether to choose RTK or GPS.

Point 2: Choose Based on the Work Content

Even at the same site, the optimal positioning method changes depending on the work being done. If you overlook this and uniformly decide between RTK or GPS on a site-by-site basis, it can lead to poor usability and insufficient accuracy. What’s important is to consider the task as the unit, not the site.

For example, when it comes to understanding current conditions, keeping patrol records, making simple updates to equipment ledgers, or performing wide-area visual checks, work speed is important. For these tasks, a highly mobile GPS is well suited. Even if there is some error, being able to confirm positions on a map afterward is often sufficient, and the ability to efficiently cover a wide area is more valuable.

On the other hand, for tasks such as layout marking, setting out positions, exact reproduction of inspection points, as-built control, pre- and post-construction comparisons, and verification of consistency with drawings, positional reproducibility is important. For these kinds of tasks, RTK, which can determine positions on-site with high precision, is advantageous. This is because when the same location is checked on a different day, it is required that the position can be traced using the same reference.

One thing to be aware of is that, within a single operation, there are situations where it’s better to use RTK and GPS together. For example, you might use GPS for the initial wide-area survey and to identify candidate locations, then use RTK to acquire only the critical points with high precision. Adopting this approach removes the need to measure everything at high precision and makes it easier to strike a balance between efficiency and quality.

What matters for practitioners is not using positioning equipment itself, but completing work safely and without waste. Therefore, it is important to consider separately which stages require what level of positional accuracy. By organizing tasks by stage—on-site verification, recording, construction management, and preparing report materials—it becomes clear where RTK is necessary and where GPS is sufficient.

Point 3 Choose Based on the On-site Environment

When choosing between RTK and GPS, verifying the site environment is indispensable. Even methods that are theoretically highly accurate may not deliver the expected results if site conditions are poor. Satellite positioning in particular is easily affected by sky visibility and surrounding reflective environments, so neglecting the site environment makes failure more likely.

In open areas, both RTK and GPS are relatively stable and easy to use. However, near buildings in urban areas, in heavily wooded locations, in mountainous regions, beside retaining walls, under bridges, and in areas with dense equipment, conditions for receiving satellite signals tend to deteriorate. In such places, it can be difficult to obtain a stable fixed solution with RTK, and GPS positioning can show greater variation.

What’s important here is not to assume that RTK is highly accurate everywhere. RTK is a method that can achieve high precision, but it only delivers its true performance when conditions are favorable. In locations where the sky is not sufficiently open, extending the observation time may still fail to produce the expected results. In such places, you need to decide to slightly move the observation position, combine it with other methods, or operate in a way that does not rely too heavily on satellite positioning at that site.

The same applies to GPS: although it is suitable for obtaining a broad overview of a wide area, positions can become unstable in poor field conditions. Therefore, even for patrols or ledger updates, it is safer not to treat the acquired positions as absolute, but to use them in combination with photos, notes, and cross-references to nearby landmarks.

When evaluating an on-site environment, it’s good to check the openness of the sky, surrounding tall structures, tree cover, ease of communications, and how easy it is to walk and move around. Not only satellite reception, but also the ease of performing the work itself affects practical quality. In other words, choosing based on whether performance can be reproduced on-site, rather than on desk-based performance comparisons, is the quickest way to avoid failure.

Point 4 Choose Based on Immediacy

When choosing a positioning method, how quickly results are needed is also an important consideration. RTK's strength is that it makes it easy to confirm high-precision coordinates on the spot. Because you can view the results immediately after acquiring the position and make decisions while checking them, it is well suited to tasks that require immediate on-site decisions, such as construction or inspection work.

For example, if you want to check on-site whether the work position has shifted, it can be too late to review the position later during post-processing. If you want to make corrective decisions and hand off to the next process on-site, RTK’s immediacy is useful. It also has the major advantage of reducing the need for revisits and making it less likely to interrupt the workflow.

On the other hand, GPS is suitable for conveniently recording positions, but caution is necessary when using it to make precise judgments on the spot. Even if a position is shown on the screen, how much you can rely on that value depends on the intended use. While it is convenient for wide-area patrols and noting locations, it can be insufficient as the basis for precise decision-making.

In practical work, there are many situations where both immediacy and the required accuracy must be satisfied. In such cases, RTK is effective, but conversely, if you are not making detailed judgments on site, the convenience of GPS can win out. For example, if the workflow is to first record the position and later organize it together with other information, it is not always necessary to fix a high-precision value on the spot.

What’s important is to be clear about what will be decided on-site. If you will fix positions on the spot and proceed with the work, lean toward RTK; if you only want a rough understanding on-site and will do detailed processing later, lean toward GPS—this is the basic way of thinking. Misjudging the required immediacy can lead you to choose an unnecessarily high-performance operation, or conversely to collect data that can’t be used for on-site decisions, so this is a point you should always confirm.

Point 5: Choose based on the operational structure

Whether RTK or GPS is more suitable depends on the number of people on site, their skills, and your company's operational structure. If you choose based on performance alone, it won't take hold on site unless you have a system in place to actually manage it. Rather than high-end features that can't be handled, a system that can be used continuously will lead to better results.

While RTK can readily achieve high accuracy, it requires operational understanding such as checking the positioning status, understanding correction information, handling coordinates, and assessing the observation environment. It does not necessarily yield the same quality regardless of who uses it, and without consistent rules and training, results can vary between operators. In particular, when multiple people use it on site, if the decision to start observations, criteria for re-observation, and recording methods are not standardized, the reliability of the data will not be stable.

By contrast, GPS is relatively easy to introduce and tends to impose a lower training burden. For basic uses such as location notes and on-site verification, operational rules can be kept simple. Therefore, when there are many field personnel and you want it to be used widely in a short time, GPS-based operations can be easier to adopt.

However, this does not mean that GPS is superior. What is important is who in the company is responsible for which tasks and what level of data quality is required. For example, it can be effective to have on-site personnel use GPS for routine record-keeping while staff who can handle RTK take care of checks that require high precision. By dividing roles in this way, you can balance accuracy and efficiency within a manageable structure.

When designing a system suited to the site, it is more important to decide who will use it, how it will be recorded, how it will be checked, and where quality will be assured than to focus on the equipment itself. The choice between RTK and GPS is both a technical selection and an operational design decision.

Point 6: Choose based on communication conditions

In RTK operations, communication conditions have a major impact. Whether correction information can be received stably is directly related to ease of use on site. Even in open areas, observations may not proceed as expected in areas with unstable communication. Conversely, GPS, when used alone for positioning, is less dependent on communications and can be easier to use in sites with challenging communication environments.

What should be noted here is that being able to see satellites and having stable communications are separate issues. Even with a wide-open sky, RTK operations can become less convenient in mountainous areas, some development sites, environments close to underground structures, or areas with unstable communications. Even if accuracy is high in theory, it is difficult to use in practice if it cannot be used continuously on site.

On the other hand, because GPS makes it easy to obtain a rough sense of position even without communications, it is effective in situations such as wide-area patrols and preliminary surveys. In particular, at the stage when you first want to grasp locations roughly, a simple method that is less affected by communication conditions is useful. Furthermore, by operating so that only critical points are surveyed with RTK on a separate schedule, you can proceed flexibly in a way that suits on-site constraints.

Developing a habit of checking communication conditions in advance is extremely important for effectively using RTK. If you only notice after arriving on site that the connection is unstable, the entire work plan can be thrown off. Therefore, at sites that rely on RTK, you should evaluate signal availability, connection stability, and how prone the link is to dropping while in motion.

Communication conditions can determine practical success or failure in ways not apparent from the specifications alone. When deciding between RTK and GPS, it is essential to check not only positioning accuracy but also whether the conditions needed for continued use on site are in place.

Point 7 Choose according to the intended use of the deliverable

Considering what the acquired location information will ultimately be used for makes the choice between RTK and GPS even clearer. If you enter the field without clarifying this, you may finish the work itself but find that the data is difficult to use in downstream processes.

For example, for uses such as internal location notes for sharing, high-level management of inspection histories, or geotagging on-site photos, location information obtained from GPS can be sufficient. The important thing is that you can trace the approximate location later. For these kinds of deliverables, ease of recording and continuity can be more valuable than precise coordinate alignment.

On the other hand, for data intended to be overlaid with design data or existing drawings, data retained as construction records, and data that will serve as the basis for future re-surveys or comparisons, RTK is appropriate. This is because it is important that another person later can reproduce the same position and that discrepancies with other data are minimal. The closer a deliverable approaches a formal management document, the higher the required reliability of its positional information.

Also, the intended use of the deliverables should take into account not only current use but also future use. Even if they appear to be mere reference records at present, they may later serve as materials for evaluating design changes or for updating maintenance ledgers. With that in mind, it is highly valuable to at least record critical locations using RTK.

On-site, it's not uncommon for data obtained initially as simple records to be repurposed later for other uses. Therefore, it's important to ensure that anyone can tell how trustworthy the data is. Simply distinguishing and managing whether a position was acquired by GPS as an approximate position or by RTK as a high-precision position can reduce confusion in later stages.

Point 8 Choose based on future scalability

When choosing between RTK and GPS, considering not only the immediate task but also future business expansion makes it less likely you'll make a wrong decision. As site digitization advances, location information will be used not on its own but linked with photos, inspection records, drawings, 3D data, construction histories, and so on. Even if simple location logging is sufficient now, higher consistency may be required in the future.

For example, even if the initial purpose is only to record patrols, later you may want to track the same positions consistently, share positions among multiple personnel, or overlay them with other positioning data. If you operate everything using only approximate GPS positions, reproducibility will be limited. Conversely, adopting an RTK approach even for just the important points will broaden the range of future applications.

Of course, you don't need to operate everything at high precision from the outset. What matters is designing a setup that allows you to raise precision incrementally to accommodate future changes. Keep daily operations simple, while ensuring high precision only for critical locations, reference points, key equipment, and aspects related to construction management. This approach secures scalability while keeping on-site burdens low.

Moreover, the value of location information increasingly depends not simply on whether it can be measured on the spot, but on whether it can be reused later. In other words, the choice between RTK and GPS is not only a positioning issue but also a question of what kind of data assets you want to leave for the future. If you are aiming for future operational improvements and labor savings, you should choose not just based on current convenience but also on whether the workflow can be built up and expanded over time.

Decision flow for selecting RTK or GPS

Considering the eight points covered so far, the choice between RTK and GPS can be organized as follows. First, confirm the positional accuracy required for the task. Next, consider whether an immediate on-site decision is necessary or whether it can be handled later. Then, evaluate the site environment and communication conditions to determine whether stable operation is possible. Furthermore, by also considering who will use it, what the deliverables will be used for, and how extensively you want to use it in the future, the criteria for selection become clear.

Viewed this way, RTK is suited to situations that require high accuracy, where you want to make decisions on the spot, where you want to increase the reliability of deliverables, and where you want to use the data as reference data in the future. On the other hand, GPS is suited to situations where you want to cover wide areas quickly, grasp approximate positions, maintain simple records, and reduce operational burden. In actual fieldwork, it is often more reasonable to use both in combination according to the workflow rather than to rely on just one.

The important thing is not to regard RTK as superior and GPS as inferior in a hierarchy. The criterion should be whether the required and sufficient level of accuracy can be ensured through feasible operations. High precision is an advantage, but it is not always the optimal choice. Conversely, a simple method can increase the burden on downstream processes if applied to the wrong use. The essence of choosing between them is selecting the method that matches the work objectives and operating conditions.

Summary

To avoid making mistakes when choosing between RTK and GPS, it is important not to judge solely by differences in accuracy. Organizing considerations from eight perspectives—required accuracy, type of work, site environment, immediacy, operational framework, communication conditions, intended use of deliverables, and future scalability—makes it easier to select the option that best fits your company's work sites.

What matters most for practitioners is less understanding the positioning method itself than determining which tasks require what level of positional information. For broad, large-area overviews, the mobility of GPS is advantageous, while for construction management and high-precision position records, RTK provides greater value. Rather than committing to one or the other, the most realistic and least failure-prone approach is to assign roles by phase of the work and use them accordingly.

If you are looking to scale up the use of location information on-site, we recommend first taking stock within your company’s operations to identify where high precision is required and where simplicity can be prioritized. By putting in place a system that is easy to use in day-to-day work and can readily support high precision when necessary, you can expand implementation benefits without strain. If you adopt options that can balance on-site ease of use with high-precision capabilities—such as LRTK, an iPhone-mounted GNSS high-precision positioning device—RTK becomes easier to operate as a practical everyday tool. Understanding the difference between RTK and GPS and then choosing the approach that suits your company’s sites is the first step to successfully leveraging location information.